System of electrical distribution.



R. P. JACKSON.

SYSTEM OF ELECTRICAL DISTRIBUTION. APPLICATION FILED DEC. 6, 1907.

1,1 1 6,430, Patented Nov. 10, 1914.

' Rig. 1

2 SHEETSSHI1ET1.

- RIP. JACKSON.

' SYSTEM OF ELECTRICAL DISTRIBUTION.

APPLICATION FILED DEC. 6, 1907.

1,116,430 I Patent d Nov. 10, 1914,.

2 SHEETS-SHEET 2.

WITNESSES:

I I mv NTOII zaatfl b aw MIMI-M ATTORNEY T alL-irhz. m it may concern UNITED STATES ATENT OFFICE? RAY r. JACKSON, or winxnisnone, PENNSYLVANIA, nssrenon, BY.MES1 \TE ASSIGN- MENTS, 'IO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, OF EAST rrr'rsnunen,

PENNSYLVANIA, A- CORPORATION OF PENNSYLVANIA.

SYSTEM 011 ELECTRICAL DISTRIBUTION.

Specification of Letters Fatent.

= Application filed December 6, 1907. Serial No. 405,379.

Be it known that L'RAY P. JAoKsor Y a citizen of the United States, and a res1- dent of Wilkinsburg, in

Allegheny and State of Pennsylvania, hare :invented' a new and useful Improvement in Systems of 'l'llectri'cal Distribution,-

of which the following is a specification.

My invention relates to systems of elec trical distribution, and particularly to systems in which generators are connected to v the distributing circuits by means of circuit hre'a-kers that are opened automatically upon the occurrence of predetermined abnormal circuit conditions.

The object of my invention is-to provide theconditions of a-circuit that the circuit-breakers therein may not be caused to open under unduly abnormal circuit conditions forwhich they are not adapted. i

Upon the occurrence of a ground or shortcircuit in a distributing system, it has frequently been found that the amountof current which traversesthe circuit rapidly becomesmore and more abnormal. For example, upon the occurrence of a ground or short-circuit upon one of a plurality of feeder circuits supplied from the same generator, substantially all of the current which the generator is capable of supplying may, within. a very short period of time, be caused to-traverse the injured circuit. Also,

when the .voltage of a circuit is governed by adjusting the" field strength of the geni means of a regulator, such, for; as that which constitutes the sub- 'erator by example: ject-matter ofIatent No. 725,800, thefield strength of thegenerator will be caused to increase veryoiiicklyby'the regulator, and the amount of current traversing the circuit is, in turn, quickly increased. If the circuitbreakers are provided with means for automatically delaying their operation a" predetermined period' of time, or are inherently slow. in operation, they :may not open until the circuit conditions-have become unduly abnormal and much more severe than those under which the circuit-breakers areadapted to open. Serious injury has, therefore, sometimes resulted tothe circuit-breakers, and it is accordingly the object of the.pres; ent inventionto prevent injuries thereto that have" heretofore resulted from this= cause. a I r Figure 1 of the accompanying drawings is a diagrammatic view of a system ofdistribution that embodies my invention, and Figs. 2 and 3 are similar views of modifications of the system of Fig. 1.

Patented Nov. 10, 1

.\ generator 1 is connected to two feeder or distributing circuits 2-'34 and 5-67 by means offcircuit-breakers 8 and 9 having tripping mechanisms, comprising magnetv windings 10 and 10 the circuits of which are similarly controlled, and it will, therefore, be necessary to describe the remainderof the system with reference to but oneot the distributing circuits.

The circuit of magnet winding 10 is sup.- plied from a battery 11, or it may be supplied from any othersuitable source, and it is governed by means of a relay switch 12 having an operating magnet winding 13 the energizing. current for which'is Supplied 'by a series transformer 14 and, is proportional in amount to that which traverses circuit conductor .7. The relay switch 12 is pro vided with a dashpot 15,. or other suitable means for delaying its closure until the ab: normal amount of current at which the switch is adapted to operate has persisted in the" circuit a predetermined period of time.

Field magnet winding 16 of the generator l is supplied from a suitable exciter. 17-having a field magnet winding 18 in the circuitof which is a resistance 19 that is normally shunted by means of a quick-acting relay switch 2 The relay switch QOis Upon the occurrence of a gr d j cuit on either of the lines 2-43- 1 h times been necessaryito provide circuit,

5 -7, practically of the current supplied by the generator may soon. traverse the the injured line, audit has, therefore,'some breakers in each line which were capable of breakingthe circuit whentraversed by the totalgenerator current. In the present instance, however, if one of the ,llnesis traversed by a predetermined amount of current the relay switch is immediately opened to include the resistance 19 in'series with field magnet winding'18 of the exciterf whereby the field strength and the volt the inj,ured circuit because of'the limitedv excitatieir of its field magnet. The switch 17 agb of the exciterare reduced.- It follows that the generator 1 cannot supply more than a predetermined amount of current to 207 'ged to operate very quickly in order ani ine resistance 19 may be inserted in. the field magnet circuit of the exciter before the switch 12 can be closed to enable the-battery to energize the tripping coil of thecircuit-breakers. Thus, thecurrent supplied to the injured line by the generator 1 will be promptly so limitedthat the circuit may subsequently be interrupted by the aircuit-breakers without injury thereto, and

cuit offield magnet winding 28" crease very materially upon with the result that the the circuit-breakers, may, therefore, be adapted for less current capacity than the total'amount of current which may be supplied by\ the generator.

.As indicated in Fig 1, the 'field strength of the exciter is manually adjustable, but,

as indicated in Fig. 2, the adjustment is effecte'd'automatically by means of a regulator of the type set forth-in Patent No.

725,800 The regulator comprises two switch members 25 and 26 for circuit'inv shuntto a resistance 2? in the cirof an ex citer 29, switch member 25 being operated by means of a, magnet winding 30 in respouse to variations in the voltage of the 'stributing circuit 32-33-3-i, and switch memben 2 6 being operated by means of a tions of the exciter volt e. The circuit in shunt to-tlie resistance 2? is also governed by means of, a nick-acting relay switch 36 that is operated y means of a magnet winding 37 when the .circuitconductor 34: is traversed by more than a predetermined amount of current. The remainder of the system is substantially like that shown in Fig. 1. If t e relay switch 36 were not provided, the voltage of thecircuit 32'33 -34 would dojthe occurrence "of a ground or short-circuit therein, and the regulator switch members 25 and 26 would, consequently, be maintained in engagement, field strengths of the exciter and the generator would be very materially increased, so that,

by the time the overnjng a agnet winding 35 in response to variais included in circuit with;

circuit-br akers 38-could be causedfto open,

the current: traversing the circuit might greatly exceed that which the circuit-break ers are adapted to interrupt. The relay,

switch 36., however, prevents the suddeudm l current traversing crease in the amount of I the circuit, by opening the circu t m'gsliunt to the resistance .27 upon the occurrence of i the predetermined abnormal circuit ,condit-r tions and b strengths oft e to be reduced.

thereby causing the field exciter and of the generator The switch 36 operates-very, quickly 'in order that the generator" field strength may be reduced before sufiicient time has elapsed foropening the cirtmit I v i :80

When two or more distributing dines are breakers 38.

supplied from the same generator, the resistance employed in connection "with the I regulating device in the' .field c1r-'- voltage cuit of the exciter ma not be sufiicient to; causethe desired re notion in the field strength of the generator upon the occu rence of a ground or short-circuit. In 3, therefore, an additionalvfiresistance 40 winding 41 of the aresistance new is relay switch 44 that-is operated-j when the circuit is traversed than, a predetermined amount of re edy switch 36 of shunt circuit to the-resistancedZ. In this afie g' t exciterii! "additionemployd inconnecition with a voltage regulator 43, there v sistance 40' being normally" shunted by.

f more; current,

together with a switch-45, similar "to {the Fig. 2, which opens the;

mariner, 'su-fiicient resistance 'is Iintreduced cult, a generator, and circuit-brcakers .necting the generator to the circuit fimff means for causing the circuit-breakers to cuit'conditions for a predetermined rind of time, and means for promptly redli cing the field strength of the generator upon the occurrence of the said abnormal circuit conitions. 1 '4 2. The combination cuit, a generator, and meeting the generator to the circuit, of means for causing the circuit-breakers too en upon the persistence of abnormal circuit Yc ondi-' circuit of the exjciter with an electric cit I strength of the generatorthat the current traversing an injured 165" at which the circuitbreakers 1 .open upon the-persistence of abnormal cirr with an electric cirg circuit-breakers con 1 25 tions of a an exclter Corrections h Letters l atent No.1 ,1 16,430.

redetermined period oftime,

' subscribed my na nie this 23rd day of R0- or the generator, a. resistance,

vember, 1907 I and means for introducin the resistance; f into the field ma et circuit of the exciter RAY JACKSON 5 'promptly upon t e occurrence ofthe said Witnesses-z 1 abnormal 'circuit conditions. I -H. B. Hanna, 1 In testimony whereof, I have hereunto 'Bmrinx Him.

- 1-1 ie hereby certified that in Letters Petent No. 1,116,430, grantedNofierober 10, I

1914,11 pon the application :0: Ray R Jackson, of Wilkinb irg; Penneylvanie, for

an improvement in printed sneeificetio -equi ring correction a's followspBegea' -iine 1;, for the word t read f and that the said Letters Petent shotild be read with this correction therein that the same may conforn to tl ie record of the oe'se in the Patent Gflioe;

Signed and sealed this 15th day of beget-MA. 1)., 19:14.

[SEAL] JJ. T. NEWTON,

Acting Commissioner of Patents.

Systerfis of Eleetrieal Distribution, en error appears in the 

